Category Archives: weka

I’ve been working with the weka java machining learning algorithms, and with the large amounts of data extracted from databases via SQL, I’ve been running into the issue of having null values. In order for the data to be read by weka, they nulls need to be replaced with a value, which in my case, should be 0.

Here is a sample of one row of my data: 2725079062,2,77,,,,,,,,,,,,,,,4,2,2,,t
There are many ways to do this, here is a common approach:

mylines=mylines.replaceAll(",,", ",0,");

however what I was running into is that if there are multiple “,,” it doesn’t parse correctly. Below is how I solved it: